Level.



C. A` CURTIS.

LEVEL.

APPLICATION FILED ms. s. 19u.

1,238,991 Patented sept. 4, 1917.

UMT'ED sTATEs PATENT 'oEEIoE CHARLES A. CURTIS, 0F LOUISVILLE, KENTUCKY.

LEVEL.

To allr 'whomffz't may concern:

Be it known that I, CHARLES ALBERT CpnTrs, a citizen of the United States, residing at Louisville, in the county of Jeli'er son and State of Kentucky, have invented ycertain. new and useful Improvements yin Levelsgof `which the following is a specilication) This invention relates to levels such as are used by carpenters, machinists, miners and others.

horizontal position and the degree of variance therefrrnn.VA

An'other object is the provision of a level, which may without adustment be used upon either horizontal sur aces, or surfaces arranged at any angle to the horizontal.

lWithin the scope of the ap ended i, Af further object is the provision of a device adaptedft accurately indicate when a surface upon `which it may be laced, is level, or plumb, and also yto indlcate to a degree the angle of the plane of said surfacea 1 A still further object is the provision in a level of the character described of means whereby' the indicator may be locked in Josition permitting a reading to be taken a ter the level is removed from the surface.

With the foregoing and other objects in view, the invention consists of the'novel Lconstruction and arrangement of parts illustrated in the accompanying drawingr which forms a part of this specification, wherein is set forth an embodiment of the inventil, but it is to be understood that such changes and modifications may be resorted to as come claims.

In the accompanying rawing, wherein similar reference .characters designate like parts in the several views, Fig. 1, is a front elevation of an embodiment of the invention: Fig. 2, a central transverse section of same on an enlarged scale: Fig. 3, a central transverse section` of a modification, on an enlarged` sealer', Fig.` ya perspective view of the tubular post shown in Fig. 2: Fig. 5, a perspective view'of the tubular post shown in a u Y,

Re erring now .in detail to thegdravfmg,

the reference -Ignates a Specication of Letters Patent.

uf'the bolt, has a tendency Patented Sept. 4, 1917.

Application led February 9, 1917. Serial No. 147,519.

stock, which may be of usual, or of any desired construction; as illustrated it is provided with one straight edge 2, `but it is to be understood that both edges may be straight edges. The stock is provided with u central chamber-3, which is closed on one side by a back plate -4 and on the other side by a transparent medium *5 such ns glass. A tubular post -6- is extended from the back plate 4 centrally of the chamber. A pendulum, or plumb-bob -7-is mounted on the post 6 and is adapta ed to swing thereabout Athrough a complete circle. That accurate indications* may be had, it. is necessary that the bob Should swing freely, consequently it is provided with antifriction bearings. In Fig. 2, the antifriction hearings are illustrated as comprising balls -8- positioned respectively between a ball race 9- positioned on the back plate, about the post, a ball race lO- positioned on the post near the forward end thereof, and coperating ball races 1lin the bore -12-'- of the hub I4- of the bob. A spirit tube -15- is carried by the bob whereby it may be ascertninediif the bob hangs true. The bob is provided with a sight opening 16- through which may be observed degree marks on a scale -17-. At times it is necessar to use a level in positions where it is di cult to see the scale. To overcome this trouble Ihave provided means for locking the bobjin position so that the reading may be ln ade after the level is removed. `Agg'illustrated in Fig. 2, the locking means conprissa bolt 1S- extending through e post and having lateral pins -19-:near the forward end which extend through longitudinal slots -20- in the forward end of the post, and are ada ted to be brought against the outer ends ofp the hub 14. The rear end of the bolt 18 is provided with screw threads -21- on'whieh a thumb lever 22- is mounted." yIt is obvious that a slight rotary movement of the thumb lever will draw the pins 19 against the hublof the plumbbob .anddock 1t in position. The rotary movement of the thumb lever, on the "-tliread parta rotary movement to the bolt, willie would be imparted to the plumb-bob by heV con- 'tact of the pins 19 therewith thereby destroying the accuracy of readings, were it not that rotary movement of the bolt is pre- `It is evident that downward In Fig. 3, I have shown a modified method of mounting and locking the plumb-bob. In this case the tubular post is provided with spaced circumferentia ribs, or -30- which are narrow and oder ve httle friction. The pos't is also provi ed with a shoulder -31-. The bore of the plumbbob fits properly over the rings 30, and projects beyond the forward end of the ost.4 A bolt 32- is provided on one end with a head 33- which is adapted to be brought to bear against the end of the hub of the bob, and near the other end is provided with a transverse slot B4- A wedge shaped member B5- positioned in the slot 34I bears respectively against the outer surface of the back plate 4 and the yend of the slot. ressure on the wedge will draw the bolt ackward and clamp the lumb-bob between the head of the bolt and) the .shoulder 31 on the post. A spring -36- serves to normally7 hold the bolt 1n its forward position with the head of the bolt clear of the hub of the bob. A projection -37- serves to prevent the complete withdrawal of the wedge, and guides may be provided to prevent any lateral movement thereof. The back plate -is recessed to accommodate the bolt operating means whereby the level may be laid down fiat:

Itis thought that the mode of operation and the many advantages of my invention may7 be understood from the foregoing descm tion. Y

y aving thus described my invention so that those skilled in the art pertaining thereto may make and use the same, I` claim:

1. A level comprising a chambered stock, a back plate closing said chamber, a tubular post vextended into said chamber, a

lumb-bob mounted on said post, a spirit lbvel carried by said bob, a scale, the bob having a sight opening through which said vdnted b reason of the 19 be' seated scale may be read, and means extended in the ots 20 in the orward en of the through said post for locking the bob against post 6. movement.

`2. A level comprisin a chambered stock, a back plate closing sai chamber, a tubular goet extended into said chamber, a plumbob mounted on said post, a spirit level carried by said bob, a scale, the bob having a sight o enin through which said scale may be rea a bo t extending through said ost, a member extended laterally from said olt, and means associated with the bolt exteriorly of the chamber and ada ted to bring said member into contact wit the bob to lock same against movement.

3. A level comprising a chambered stock, a tubular post extended into the chamber, a plumb-bob mounted to swing about said post, a sliritlevel carried bf said bob, a

olt slide ly mounted in sai post, means associated with the bolt and adapted to shift it longitudinally, and means connected therewith and adapted to be engaged with the bob to lock it against movement.

4. A level comprising a chambered stock, a back plate, a tubular post extended from said plate into the chamber, a weighted member mounted to swing about said post, a bolt slidably mounted in and extended through said post, a. head on said bolt adapted to be engaged with said member, and means associated with the bolt and ada ted to actuate same to cause the said hea to engage the weighted member and lock it against movement.

5. A level comprising a chambered stock, a back plate, a tubular post extended from said plate into the chamber, a weighted member mounted to swing about said post, a bolt slidably positioned in and extended through said tu ular post a head on said bolt adapted to be engaged with said member, the bolt havin a transverse slot near its rear end, a w ge operable in said slot and adapted to slide' the bolt backward, and a spring adapted normally to maintain the bolt in its forward position.

CHARLES A. CURTIS. 

